Extension-trestle



(No Model.)

B. M. WALKER.

EXTENSION TRESTLE.

No. 357,879. Patented Feb. 1 5,v 1887.

INVENTOR fi/z M 1 ATTORNEYS WITNESSES II. PETER5, Phum-Lilhngrlphur. Washlngion. ac.

UNITED STATES PATENT OFFICE.

REASON MELVIN WALKER, OF GREEN CAMP, OHIO.

EXTENSlON-TRESTLE.

SPECIFICATION forming part of Letters Patent No. 357,879, dated February 15, 1887.

Application filed September 28, 1886. Serial No. 214,742. (No model.)

To aZZ whom it may concern.-

Beit known that I, REASON MELVIN WALK- ER, a citizen of the United States, and a resident of Green Camp, in the county of Marion and State of Ohio, haveinvented certain new and useful Improvements in Extension-Trestles; andI do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon,which form a partof this specification.

Figure 1 of the drawings is a representation of this invention, and is a front view. Fig. 2 is a side view.

This invention relates to extension-trestles for plasterers use; and it consists in the con struction and novel combination of devices, as hereinafter set forth, and pointed out in the claim.

In the accompanying drawings, the letter A designates the legs of one of the scaffold or trestle supports, which are secured at their upper ends to a head-block, B, and diverge downward, being braced below by the bar 0.

D D are guide-bars arranged vertically and parallel to each other, and secured to the head B and bar C. An interval, E, is left between the guidebars for the slide F,which is usually flanged to engage grooves of the guides, so that it will not fall out of place. The slide is provided with downwardly-beveled teeth, as indicated at'g, along its outer edge, as shown, and at its upper end is provided a bearing or bearings for the girder or horizontal bar which connects this support to another. Usually,

apertures 71. are provided in the bearing or 40 head of the slide-bar for screws.

To the head-block are connected the ends of the bail-catch K, the ends of which may be formed with eyes engaging staples driven into said head-block. This catch is designed to hang downward and engage one of the notches of the slide-bar, according to the height at which it has been adjusted.

In order to raise the slidebar, a short handle-lever, L, is used. This is forked, its arms being pivoted to the guide-bars. It is provided with a pivoted tongue, m, which is kept in contact with the slide-teeth by a spring. when operated, the lever will raise the slide, which will be caught and held as it is raised by the bail-catch. In order to lower the slide the bail-catch is disengaged, so that the slide can descend. Its descent may be easily regulated by the lever.

Having described this invention, what I claim, and desire to secure by Letters Patent, 1s-

The improved trestle herein described, consisting of two frames composed each of a frame formed of the legs A, a crossbar, O, securing the lower ends of the legs, and the head-block B, securing the upper ends of the said legs, which converge upwardly, the vertical and parallel guide-bars D D, secured to the lower cross-bar and head-block, the forked handlelever having its branches pivoted to said guidebars and carrying a spiingpressed dog, the bail catch pivoted to the head block, the toothed slide-bar, and the bearing secured to the upper end thereof for the attachment of the girder, substantially as specified.

In testimony whereof I affix my signature in presence of two witnesses.

REASON MELVIN WALKER.

Witnesses:

T. H. PHILLIPS, M. L. MARTIN. 

